This grant provides core support for a program on trace contaminants with special emphasis on heavy metals. Several interrelated research programs in Environmental Toxicology have made the Center a necessity, both scientifically and administratively. The core services provided by the Center include analytical and histopathological laboratories, pharmacokinetics modeling, biomathematics, and central administration of the various programs. The Center also provides resources to develop embryonic research ideas to the point where independent support may be obtained. The core faculty provide long-term continuity of professional expertise and experience in the Environmental Health Service field, to provide a national resource ready to respond to urgent needs in the Environmental Health Field. The research in the Center is restricted to those trace contaminants most likely to affect human health. The Center is continuing to concentrate on the toxic heavy metals (Cd, Hg, and Pb), in continuation of well-established research projects at Rochester with the support of a program project grant from NIEHS. BIBLIOGRAPHIC REFERENCES: Clarkson, T. W. Factors Involved in Heavy Metal Poisoning. Federation Proceedings 36 5:1634-1639. 1977. Amin-Zaki, L., Elhassani, S. Majeed, M. A., Clarkson, T. W., Doherty, R. A. and Greenwood, M., Giovanoli Jakubezak T., Perinatal methyl-mercury poisoning in Iraq. Am. J. Dis. Child. 130 1070-1076, 1976.